Set value of a switch with Firestore boolean - firebase

Question

I'm making a test app that switches a boolean value in Firestore. I need the app to retrieve the initial value of the switch from Firestore. Through my method, I get the error type 'Future' is not a subtype of type 'bool'. The Boolean value is called LEDOn. Here is my app:
import 'package:flutter/material.dart';
import 'package:cloud_firestore/cloud_firestore.dart';
void main() => runApp(MyApp());
class MyApp extends StatefulWidget {
#override
State<StatefulWidget> createState() {
return _MyAppState();
}
}
class _MyAppState extends State<MyApp> {
final db = Firestore.instance;
void updateLED(bool newValue) async {
await db
.collection('LEDStatus')
.document('LEDStatus')
.updateData({'LEDOn': newValue});
}
Future<dynamic> checkLEDStatus() async {
DocumentSnapshot snapshot =
await db.collection('LEDStatus').document('LEDStatus').get();
return snapshot.data['LEDOn'];
}
#override
Widget build(BuildContext context) {
return MaterialApp(
theme: ThemeData(brightness: Brightness.dark),
home: Scaffold(
appBar: AppBar(
title: Text('Thingspeak'),
),
body: Column(
children: <Widget>[
Switch(
value: checkLEDStatus(),
onChanged: (bool newValue) {
setState(() {
print(newValue);
updateLED(newValue);
});
})
],
),
),
);
}
}

Answer 1

Use a FutureBuilder. Also, change your checkLEDStatus() return type to Future<bool>.
FutureBuilder(
future: checkLEDStatus(),
builder: (context, snapshot) {
if (snapshot.connectionState == ConnectionState.done) {
bool result = snapshot.data;
return Switch(value: result, onChanged: (bool newVal) {
setState(() => result = newVal);
updateLED(newVal);
});
} else {
return Center(child: CircularProgressIndicator());
}
}
)

Answer 2

The Switch widget has the property value which takes a value of type bool. Currently in your code you are returning a Future and that's why you get that error. It should be like this:
Switch(
value: isSwitched,
onChanged: (value) {
setState(() {
isSwitched = value;
});
},
You can retrieve the boolean value from firestore inside the initState and then assign it to the property value. Then when the user switches inside setState() call the update method and do isSwitched = newValue